Energy-related Greenhouse Gas Emissions Research Articles

Multi-Aspect Shaping of the Building’s Heat Balance

In the European Union, buildings account for 42% of the energy consumption and 36% of the direct and indirect energy-related greenhouse gas emissions. Reducing thermal power for heating purposes is crucial to achieve climate neutrality. The main purpose of this article is to identify the places in the building where it is possible to significantly improve energy efficiency through the use of appropriate construction and material solutions. This article contains a multi-aspect approach to the heat balance of a building. Solutions that have a direct impact on building energy consumption were analysed, taking into account architectural, technological, and material aspects. Particular attention was paid to energy-efficient design and material solutions for non-transparent and transparent external walls and thermal storage walls (Trombe walls). An analysis of heat transfer through building elements was carried out, along with the optimisation of energy-efficient solutions for non-transparent and transparent barriers. Two methods for determining the equivalent heat transfer coefficient Ue for solar active partitions are presented. The analysis presented in the work using the original method of the balanced heat transfer coefficient Ue is a testing ground for identifying unfavourable features of the building structure, as well as the most energy-efficient solutions that can be used in establishing standards for the construction and modernisation of buildings. The value of the Ue coefficient illustrates the actual heat transfer through the partition. Having Ue values for various structural solutions of building envelopes, the designer can easily select the most effective ones. The use of the presented methodology will allow for the optimisation of technical solutions for building elements to improve its energy efficiency.

A Grand Challenge: Net-Zero Operations—Changing the Definition of “Business as Usual”

_ This is the second of a series of six articles on SPE’s Grand Challenges in Energy, formulated as the output of a 2023 workshop held by the SPE Research and Development Technical Section in Austin, Texas. Described in a JPT article last year, each of the challenges will be discussed separately in this series: geothermal energy; improving recovery from tight/shale resources; net-zero operations; carbon capture, storage, and utilization; digital transformation; and education and advocacy. The first article, “An SPE Grand Challenge Update on Geothermal Energy,” was published in April 2024. _ At COP28, more than 50 oil and gas companies, many of them national companies, took a historic step toward decarbonization by launching the Oil & Gas Decarbonization Charter. The charter represents significant short- and long-term ambitions to reduce emissions, including net-zero operations by 2050 at the latest. This article explores the importance of this effort, the opportunities available to the industry to reduce its Scope 1 and 2 emissions, and the key technologies needed to achieve the net-zero goal. The Size of the Prize According to the latest data from the International Energy Agency (IEA), the production, transport, and processing of oil and gas resulted in 5.1 GtCO2e in 2022. These emissions stem from the production and delivery of oil and gas and the combustion of fossil fuel necessary for operations on-site (Scope 1), and the import of electricity from external sources consumed in oil and gas facilities (Scope 2). These Scope 1 and 2 emissions represent just under 15% of global energy-related greenhouse gas (GHG) emissions. This is a sizable contribution, nearly equivalent to all energy-related GHG emissions from road transport, highlighting the relative scale of the opportunities associated with implementing operational changes in the industry. The faster and deeper these emissions reductions are, the more significant the impact will be. Sources of Emissions To understand the various paths to net zero an oil and gas company can follow, it is critical to map the sector’s sources of emissions throughout the value chain. It is generally recognized that around 60% of an integrated company’s emissions emanate from upstream operations, predominantly from onshore assets. Refining and distribution are the second main contributors, but of a smaller order of magnitude, notably because of significant efforts already made by companies to reduce emissions from their refining assets and levers of decarbonization potentially easier to implement. However, emissions volumes and intensities differ significantly across regions, countries, and asset types. An asset operating in the Canadian oil sands region will have a very different emissions profile compared to an offshore platform in Western African countries. These differing profiles also call for tailored emission-reduction approaches. This means decarbonization studies must be carried out at the asset level, allowing operators to identify the most cost-effective means of tackling emissions reduction.

Achieving a circular economy through the effective reuse of construction products: A case study of a residential building

The building and construction industry is characterized by high consumption of raw materials, waste generation, and significant energy-related greenhouse gas emissions. A substantial change in the way this sector operates is necessary to reduce its strong negative impact on the environment. In this context, the implementation of circular strategies is critical to achieving sustainable development. Reusing construction products derived from obsolete buildings at their end of life is increasingly being investigated as a strategy to achieve circularity. Despite growing interest, both in the literature and in the industry, several challenges hinder the large-scale adoption of circular reuse. The purpose of this study is to contribute to the efficient implementation of reuse in practice. The focus is on data and information that can support the reusability assessment of construction products. The findings are obtained through a case study comprising a building project in Bergen, Norway. First, the study assesses which material properties and information are available in the project, leading to the definition of eight information-driven evaluation criteria and a three-step process for reuse. The three-step process encompasses the following: (1) collecting information, (2) information-driven evaluations, and (3) planning for reuse. Each criterion is then shown in a reusability matrix, emphasizing an information-driven approach to reuse that has the potential to be extended beyond the context of the case study. Considerations for improving data management in a circular reuse process are discussed. This study provides an innovative method that may lead to a circular economy and sustainable development in the future.

A multi-scale lifecycle and technoeconomic framework for higher education fleet electrification

Transportation accounts for one-quarter of all energy related greenhouse gas emissions. As it pertains to transport electrification, higher education institutions—such as universities—can model solutions that affect broader society. Despite this, higher education’s role in fleet electrification adoption has been understudied. We, therefore, modeled an archetypical higher education institution to analyze the carbon and economic payback periods of three electrification scenarios (Business-as-Usual, Targeted Electrification, and Full Electrification) using a cradle-to-grave lifecycle and technoeconomic approach. Given the archetypical higher education institution fleet of 368 vehicles, results show an economic ratio plateau point of about 8 years at 20 fuel-based cars replaced by electric vehicles and a carbon payback period peak of roughly 10 months at 50 fuel-based cars replaced. We then performed a multi-scalar analysis by leveraging implementation theory. We find that higher education institutions that adhere to the tenets of implementation theory are poised to be pro-environmental change agents in many regions and countries. The methods and findings herein can be adapted to other institutions, regardless of fleet size, and can bolster relevant decision-making outcomes now.

Is sustainable energy development ensured in the EU agriculture? Structural shifts and the energy-related greenhouse gas emission intensity

The changes in energy use and energy-mix are important in ensuring the implementation of the sustainability goals, especially those related to the climate change. Even though there have been attempts to analyse the energy-related greenhouse gas (GHG) emission in the European Union, there is still a lack of research that considers structural change, fossil energy consumption, and energy-mix simultaneously. In this context, the present paper addresses the growth in energy-related greenhouse gas (GHG) emissions in the European Union (EU) agriculture. The index decomposition analysis based on the logarithmic mean Divisia index is implemented over the period of 2004–2021. The change in the GHG intensity at the EU level is factorized with respect to the structural effect and those related to the energy intensity, the share of the fossil energy, and carbon factor for the fossil energy. The results suggest that a decline in the energy intensity appeared as the main driver pushing the energy-related GHG emission intensity down in the EU agriculture. This calls for further actions directed towards the increase of the use of renewables.

Modelling & Spatial Mapping of Residential-Sector Emissions for Sub-National & Urban Areas

The residential sector accounts for 33% of energy-related Greenhouse Gas (GHG) emissions globally and must undergo rapid emissions reductions in order to support broader society-wide sustainability and net-zero transitions. Additionally, urban areas account for approximately 70% of global GHG emissions. To provide a baseline for urban climate action plans and mitigation strategies, sub-national municipalities must quantify their sectoral baseline emissions in detail and develop strategies for reducing emissions relative to these baselines. Therefore, it is important to establish clear methodologies for computing these baselines in accordance with the best available science. This paper establishes a novel methodology for developing a residential sector emissions model using a data-driven and spatial mapping approach. This would form an important component of future multi-sectoral baseline emissions inventories.•The residential sector emissions model combines publicly available census and building energy performance datasets in order to model and visualize the distribution of energy demand and resultant emissions across an urban study domain in Ireland.•The methodology presented was developed in line with the approaches and requirements of the Global Covenant of Mayors and the Intergovernmental Panel on Climate Change.•It is envisioned that this residential sector emissions model methodology could be applied in any urban area worldwide.

SLiCE: An open building data model for scalable high-definition life cycle engineering, dynamic impact assessment, and systematic hotspot analysis

Building construction and operation are responsible for around 40 % of global energy-related greenhouse gas emissions. To identify emissions reduction and removal potentials as well as wider environmental impacts, researchers, policy, and decision makers need comprehensive life cycle sustainability assessment (LCSA) insights on individual buildings and building stocks at large.This article proposes an open building data model for Scalable, high-definition Life Cycle Engineering (SLiCE) as a solution to overcome the limitations identified for existing models. The article departs from conceptualizing the problem within the Space-Time-Indicator Nexus; presents the proposed SLiCE data structure; and showcases practical uses of SLiCE data for dynamic assessment of climate change impact as well as for systematic environmental hotspot analysis.The open SLiCE building data model and SLiCE hotspot analysis tool are henceforth available for implementation within life cycle assessment (LCA) of building and building stocks, enabling comprehensive insights on buildings' environmental impacts across spatiotemporal scales.

Pathways to Clean Energy Transition in Indonesia’s Electricity Sector with Open-Source Energy Modelling System Modelling (OSeMOSYS)

Responding to the Paris Agreement and climate change mitigation, Indonesia aims to reach net zero by 2060 or sooner. Due to Indonesia’s dependence on coal and growing consumption, alternative sources of clean energy are imperative for meeting its rising energy needs and reducing energy-related greenhouse gas emissions to achieve the energy transition. This project aims to examine Indonesia’s opportunities and potential to achieve low carbon ambition in the energy sector and identify alternative pathways for the energy transition in Indonesia. In this study, the open-source energy modelling system (OSeMOSYS), which is a long-term energy system modelling tool, is employed to compare electricity generation, investment, and carbon dioxide emissions between business-as-usual and five alternative scenarios. Six scenarios, including business as usual, least-cost, two coal-phrase out and two net zero aligned with national climate targets and optimal scenarios, were simulated across different target years. The results show that the net zero (NZ) scenario is more cost-effective and emits fewer greenhouse gases than the other scenarios in meeting Indonesia’s future energy demand. However, achieving net zero by 2050 (NZ50) results in significantly lower CO2 emissions (10,134 MtCO2), which is less than half of the emissions in the net zero by 2060 (NZ60) scenario (16,849 MtCO2) at a similar cost (6229 and 6177 billion USD, respectively). This paper’s insights emphasise that large-scale renewable energy deployment and coal retirement are critical pathways to reaching carbon neutrality and achieving the energy mix transition.

An advanced geospatial assessment of the Levelised cost of energy (LCOE) for wave farms in Irish and western UK waters

With the climate crisis becoming an ever-growing concern, Europe is striving to reduce its energy related greenhouse gas emissions. On the western edge of this continent, wave energy is a logical future clean energy consideration for Ireland and the U.K. to help realise ambitious targets recently being set in policy. Yet to reach commercialisation, there is still much uncertainty surrounding the financial feasibility of wave farms in the region of interest, and where exactly the most feasible locations are likely to be. The Levelised Cost of Energy (LCOE) is the most commonly used metric in determining the financial feasibility of an energy project, and it is very much site dependant when it comes to wave energy, varying considerably from one location to the next. This study uses the geographic approach to address this and estimate the LCOE of wave energy farms in the region, considering different technology types and the geospatially variable inputs at play. The results reveal areas of high project feasibility in the Atlantic Ocean (off the west coast of Ireland), the Celtic Sea and the Inner Seas off the West Coast of Scotland (ISWCS), with LCOE values below 110€/MWh along the coasts of these areas.

Household energy-related carbon footprint in residential neighbourhoods in high-latitude cities: A case of Edmonton in Canada

Understanding all the possible greenhouse gas (GHG) emission sources and factors is key to achieving net zero emissions by 2050, as targeted by the Paris Agreement, and thereby, averting the severe consequences of climate change. In this study, we explored household energy-related GHG (HEGHG) emissions in 265 residential neighbourhoods in a high-latitude city that experiences opposite temperature extremes. Our results revealed that the average annual per capita GHG emissions from dwellings in the city are 45% higher than those from personal transportation, highlighting the urgent need for greater emphasis on reducing GHG emissions from dwellings in high-latitude cities. We found that per capita floor area is positively correlated with GHG emissions. The findings also indicate that per capita HEGHG emissions significantly increase with increasing neighbourhood income levels (r = 0.8). An increase in the percentage of households struggling to afford homeownership is also associated with a decrease in HEGHG emissions (r = -0.3). These findings can help facilitate the focus on areas of high-latitude cities where the mitigation measures may have the most impact in reducing carbon footprint.

Taxing energy to tackle greenhouse gases: evaluating the role of financial risk in high-income economies

Energy, a basic input to the economic system, plays a pivotal function in development; at the same time, it raises concerns and hurdles to global economies as a result of negative externalities associated with its usage. Economies set various measures to limit these negative externalities and encourage citizens toward renewable energy utilization. Considering a panel of high-income economies over the period of 1990–2020, we empirically examine whether energy-related tax policies (ENT) are helpful to tackle the issue of energy-related greenhouse gas emissions (ENGHGs). Furthermore, we also investigate the role of digitalization (DIG) and financial risk (FINR) for its possible impact on ENGHGs. The advanced econometric techniques include diagnostic tests, Method of Moment Quantile Regression (MMQR), for robustness validation quantile regression, and finally Dumitrescu and Hurlin panel causality check. The findings reveal that ENT policies of selected economies are not helpful to limit ENGHGs in 25th and 50th quantiles effectively. Nevertheless, due to the progressive rise in ENT in the 75th and 90th quantiles, ENT significantly helps to smoothen the path towards a sustainable future. Furthermore, GDP increases, while improvement in FINR decreases ENGHGs. As the selected economies are developed and high-income, it is suggested that a progressive rise in ENT may further limit the issue of ENGHGs.

An eco-social solution to energy poverty? Substance and symbolism in the England's use of domestic energy efficiency policy to achieve social and environmental synergies, 1997–2023

Domestic energy efficiency policy is potentially a means for reducing residential energy-related greenhouse gas (GHG) emissions and expenses for households in energy poverty. It has often been presented as an eco-social exemplar, for example in the European Union's Green Deal. The European Commission regards domestic energy efficiency improvements as the primary means for addressing energy poverty notwithstanding the 2022/23 energy crisis. However, the case for domestic energy efficiency improvement as a tool for achieving simultaneously social and environmental goals is often assumed rather than demonstrated. This article uses Mandelli's eco-social trilemma heuristic and the symbolic politics literature to surface the tensions involved in such processes, focusing on policy efforts in the England between 1997 and 2023 as a case study. England is a good case to consider because it has been regarded as a leader of energy poverty mitigation and its policy approach is similar to the European Commission's. The article details the main policy instruments used in England, assesses outputs and outcomes using official statistics, government and independent policy evaluations and the secondary literature, and details the main problems encountered in achieving environmental/social synergies. Based on this analysis, the article argues that English domestic energy efficiency policy has generally constituted a symbolic eco-social policy, particularly on the social side and since 2010. Highlighted by the 2022/23 energy crisis, domestic energy efficiency policy is best regarded as one component of a policy toolkit for reducing energy poverty, which at the least should also include targeted social protection.

Guest Editorial: Brownfield Optimization The Key To Unlocking Sustainable Oil and Gas?

The topic of sustainability within the oil and gas industry has dominated news agendas in recent years. As ‘Net Zero by 2050’ goals loom closer, the sector is under greater pressure than ever to decarbonize operations and source oil and gas via more sustainable methods. With the energy transition continuing at pace, the growth of renewable energy has been exponential. Energy sources such as nuclear and wind are set to account for a greater portion of the energy mix. Renewables expenditure is also expected to double over the next 10 years to more than $1,300 billion per year, and grid expenditure is likely to exceed $1,000 billion per year in 2030. However, oil and gas will undoubtedly play a crucial role in meeting global energy demand for the foreseeable future. A recent industry report highlighted that conventional hydrocarbons are set to comprise 49% of the energy mix in 2050, emphasizing the sustained requirement for traditional hydrocarbons. It is no secret the oil and gas sector is a high producer of carbon emissions, and according to the International Energy Agency, global production, transportation, and processing of oil and gas emitted the equivalent of 5.1 billion tons of CO2 in 2022. That’s almost 15% of total energy-related greenhouse gas emissions. So, how do we as an industry continue to extract this much needed energy source in a more-sustainable manner? Methods to curb this emission are already in practice, with operators utilizing new technology to reduce waste-gas production, return the gas to on-site product streams, and reinject methane into reservoirs. A notable example came from ExxonMobil in January of this year with the company announcing it had stopped routine flaring of natural gas from production in the top US shale basin, using compressors to push natural gas to a pipeline. It has also allocated $17 billion through 2027 to lower its greenhouse gas emissions globally. Electrification is also a hot topic, with operators investigating methodologies for how to reduce emissions from offshore assets. bp, Equinor, and Ithaca Energy recently signed a memorandum of understanding to explore electrification options for their offshore production facilities in the West of Shetland area in the North Sea. Electrification solutions could include power from shore, potentially from onshore wind, or from offshore wind. Full electrification would require in the region of 200 MW of power. If successful, the fields would become the first oil and gas developments on the UK Continental Shelf to be powered by electricity delivering a fully renewable solution. These latest industry moves are bold. They certainly show that much-needed action is now taking place and that industry is responding to social and environmental pressures to make changes.

A study of energy use and associated greenhouse gas emissions in Norwegian small-scale processing of whitefish

This study considers the energy use and associated greenhouse gas (GHG) emissions at three fish processing companies, representing a seasonal small-scale whitefish processing industry within the Norwegian coastal fisheries. The primary objective is to analyse the energy use in small-scale processing of whitefish and to provide energy requirements for primary processing, freezer and freezer storage, and drying. The study also discusses the environmental importance of the fish processing stages as compared to fishing vessels in seafood value chains. The results show that initial processing and cold storage has an average energy use of 132 kWh/ton of raw material. Freezing and freezer storage and drying have energy consumptions of 449 and 203 kWh/ton, respectively. Energy use per unit of volume decreases as the amount of raw material increases. This study finds that small-scale whitefish processing may account for a significant share of the total energy consumption and associated GHG emissions from fishing vessels and processing stages. The energy related GHG emissions are highly dependent upon the electricity mix and energy sources in general. The representativeness of the results is limited given that the three companies considered in this case study operate under very specific conditions, i.e., they are small-scale actors operating within a seasonal and geographically limited coastal fishery. Future research could utilize data from a larger number of facilities and do long-term statistical analysis of energy use in different fish processing stages. The use of advanced metering systems has proven suitable for such purposes, and could be supplemented by installation of permanent monitoring equipment such as “panel servers” to record energy use for specific processes within whitefish processing.

Revealing the role of renewable energy consumption and digitalization in energy-related greenhouse gas emissions—Evidence from the G7

The massive consumption of energy promotes rapid economic growth, but it also unavoidably results in a large amount of greenhouse gas emissions, which seriously hinders society’s green and low-carbon development. This paper aims to explore the real impact of renewable energy and digitalization on greenhouse gas emissions from an energy-related perspective using advanced panel econometrics methods based on G7 panel data for 1990–2020. Economic growth and energy efficiency are also considered as control variables. Due to the nonlinear properties of panel data, the moment quantile regression approach is utilized in this research. The findings show that slope heterogeneity is widespread, section-dependent, and has a long-term equilibrium relationship. In addition, digitalization, renewable energy, and energy efficiency can reduce energy-related greenhouse gas emissions and ease environmental pressures. Economic expansion, on the other hand, remains an important positive driver for energy-related greenhouse gas emissions. The results of this study are robust and the causal relationships between variables are tested. Based on the conclusion presented above, this study advises the G7 economies to expand investments in renewable energy and digitalization to promote energy system transformation and pave the road for global decarbonization objectives to be met.

Life Cycle Assessment of the Environmental Benefits of Using Wood Products and Planting Trees at an All-Electric University Laboratory

Many countries across the globe have set targets for different economic sectors, aiming to tackle global warming by reducing the overall carbon footprint of human-related activities. Among these sectors, the building industry stands out as a major consumer of materials and energy resources, making it a key player in achieving carbon neutrality. It is one of the main contributors responsible for energy-related greenhouse gas (GHG) emissions, including both operational emissions and embodied emissions in materials and equipment manufacturing. Nature-based design solutions, such as planting trees in urban spaces, or incorporating the use of wood products, have regained attention in recent years due to their potential to mitigate carbon emissions from buildings. Within this context, this paper presents a comprehensive life cycle assessment (LCA) of a recently built research facility, with a focus on demonstrating how the benefits of nature-based solutions, specifically carbon sequestration from trees and biogenic carbon content in wood products, can be quantified and reported using the latest LCA standards and tools. The analysis is provided under three end-of-life scenarios for wood products: wood incineration with energy recovery, wood landfilling, and wood recycling/repurposing. The results indicate that the set of strategies adopted in this building, i.e., tree planting, the use of wood products, and the end-of-life treatment of materials, can potentially offset carbon emission by 37.2% up to 83.9% when included in the LCA, depending on the scenario considered. By continuing to refine LCA standards and tools, and fostering collaboration between researchers, policymakers, and industry professionals, we can advance our understanding and ultimately achieve the widespread adoption of carbon-neutral buildings.

Exploring sufficiency in energy policy: insights from Sweden

Energy efficiency and renewable energy strategies have been insufficient in achieving rapid and profound reductions of energy-related greenhouse-gas (GHG) emissions. Consequently, energy sufficiency has gained attention as a complementary strategy over the past two decades. Yet, most research on energy sufficiency has been theoretical and its implementation in policy limited. This study draws on the growing sufficiency literature to examine the presence of sufficiency as a strategy for reducing energy-related GHG emissions in Sweden, a country often regarded as a “climate-progressive” country. By conducting a keyword and content analysis of energy policies and parliamentary debates during four governmental terms of office (2006–2022), this research explores the extent to which sufficiency is integrated into Swedish energy policy, as well as potential barriers to its adoption. The analyses revealed a scarcity of sufficiency elements. Although some policies could potentially result in energy savings, they are infrequent and overshadowed by the prevailing emphasis on efficiency and renewable energy. Furthermore, Sweden lacks a target for sufficiency or absolute energy reductions. The main impediments to sufficiency implementation include the disregard of scientific evidence in the policy-making process and the perceived contradiction between sufficiency and industrial competitiveness. This study thus concludes that sufficiency at best remains at the periphery of Swedish energy policy. Given the reinforced ambitions within the European Union, this raises questions regarding the validity of Sweden’s reputation as a climate-progressive country.

Does the energy-related greenhouse gas emission abatement cost depend on the optimization direction: shadow pricing based on the weak disposability technology in the European Union agriculture

Does the energy-related greenhouse gas emission abatement cost depend on the optimization direction: shadow pricing based on the weak disposability technology in the European Union agriculture

Decarbonization in New Zealand – where and how: a combination of input–output approach and structural decomposition analysis

In New Zealand, agriculture accounts for around 50% of total gross greenhouse gas emissions, energy production and use account for 40%. Given the limited possibility of reducing methane from the agricultural sector, we focus on the shape of, and factors influencing, the energy-related emissions profile. A single framework that combines environmental input–output analysis with structural decomposition analysis is established to systematically investigate driving forces shaping energy-related greenhouse gas emissions at national and sectoral levels. Results show that emission intensity, population, and consumption volume are dominant factors influencing shifting the energy-related emissions profile from 2007 to 2013. To achieve a net-zero-carbon economy, decarbonizing the transport sector is foremost and should be given priority. Policy directed at improving energy utilization in private consumption and exports, and the adoption and utilization of advanced technology in manufacturing, would contribute to achieving emissions reduction targets.

Orphan No More—Federal Funds Begin Flowing to State Coffers for Orphan Well Remediation

Billions of dollars in federal funding secured under the 2021 Bipartisan Infrastructure Investment and Jobs Law (BIL) has started flowing into US state coffers for the plugging and remediation of orphan oil and gas wells. Signed into law in November 2021, the BIL is a $1.2 trillion “once-in-a-generation investment” that includes $4.7 billion in funding to plug and remediate orphan wells across the nation. According to the US Department of the Interior (DOI), these legacy pollution sites are environmental hazards and jeopardize public health and safety by contaminating groundwater, emitting noxious gases and methane, littering the landscape with rusted and dangerous equipment, and harming wildlife. The US Environmental Protection Agency (EPA) estimated in a 2020 inventory of greenhouse gas emissions that, on average, each unplugged abandoned oil and gas well emits 0.13 tons of methane per year. When multiplied by an estimated 2.1 million unplugged, abandoned oil and gas wells, the EPA estimated methane emissions of 276,472 tons in 2019, equivalent to roughly 9.5 mtpa of carbon dioxide (CO2) assuming a 100-year global warming potential (GWP) of 34. This is roughly 2.6% of total US energy-related methane emissions or roughly 0.2% of total US energy-related greenhouse gas emissions in 2019, assuming a 100-year GWP for methane of 34, according to a report published in Environmental Science & Technology. The Intergovernmental Panel on Climate Change defines GWP as the cumulative radiative forcing, both direct and indirect effects, over a specified time horizon resulting from the emission of a unit mass of gas related to some reference gas. While the EPA pegs the number of orphaned wells in the millions, there are variations in the count, depending on how each state or organization defines what is and is not an orphaned well. A survey, for example, by the Interstate Oil and Gas Compact Commission in 2018 put the range of orphaned and idle wells at around 560,000 to 1.1 million. According to the Railroad Commission of Texas (RRC), the regulatory body that oversees Texas oil and natural gas development, an orphan well is an inactive and unplugged well that has not produced oil or natural gas for a minimum of 12 months. But the Colorado Oil & Gas Conservation Commission defines an orphan as a well which has no owner or operator that can be found, or where the owner or operator is unwilling or unable to plug and abandon such a well. This JPT article described the hunt for the potentially hundreds of thousands of unknown, undocumented orphans across the country. In October 2021, the Environmental Defense Fund (EDF) released a map showing the location of more than 81,000 documented orphan wells in 28 states that are eligible for funding under the BIL. In the spring of 2022, thanks in part to states documenting more than 40,000 additional orphan wells, EDF released an updated map showing more than 120,000 documented orphan wells in 30 states (Fig. 1).